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Finding the Fourth Proportional to 211.40, 317.10 and 206.90

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Solution

The fourth proportional to 211.40, 317.10 and 206.90 is: 310.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    211.40 : 317.10 = 206.90 : x
  2. Step 2: Convert to fraction form
    211.40/317.10 = 206.90/x
  3. Step 3: Cross multiply
    211.40x = 317.10 × 206.90
  4. Step 4: Simplify right side
    211.40x = 65,607.99
  5. Step 5: Solve for x
    x = 65,607.99/211.40
  6. Step 6: Final answer
    x = 310.35

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.